The present invention relates to liquid level indicators in general and more precisely to those comprising an elongate member which extends vertically through a liquid container and, at least at one predetermined point of its length, is formed with a transverse portion, the weight of the member being sensed as a measure of the liquid level in the container.
Level indicators of this type are reliable but are dependent on the liquid density, and therefore a change in density will affect the indication. To be able to pay regard to changes in density, standardisation, i.e., direct or indirect determination of the liquid density is required. Indirect determination of the liquid density may be carried out for example by determining the liquid level by some other means and relating it to the liquid level established through the above-mentioned sensing of the weight. By arranging a transverse portion on the member, a change in the magnitude of the weight change per unit of time is obtainable at the beginning of the transverse portion, but this requires a relatively quick change of the liquid level.